Ultrasonic clamp coagulator apparatus having improved waveguide support member

ABSTRACT

An ultrasonic surgical clamp coagulator apparatus is configured to effect cutting, coagulation, and clamping of tissue by cooperation of a clamping mechanism of the apparatus with an associated ultrasonic end-effector. The ultrasonic waveguide of the apparatus is preferably provided with an improved support member at the distal-most node thereof, which support member desirably functions to resist bending moments created in the waveguide, attendant to operation of the clamping mechanism, while sealing the region adjacent to the waveguide.

TECHNICAL FIELD

The present invention relates generally to ultrasonic surgical devices,and more particularly to an ultrasonic surgical clamp coagulatorapparatus for coagulating and/or cutting tissue, including an improvedthin-walled support and sealing member for the ultrasonic waveguide ofthe apparatus which resists bending moments created during clamping oftissue against an end-effector of the waveguide.

BACKGROUND OF THE INVENTION

Ultrasonic surgical instruments are finding increasingly widespreadapplications in surgical procedures by virtue of the unique performancecharacteristics of such instruments. Depending upon specific instrumentconfigurations and operational parameters, ultrasonic surgicalinstruments can provide substantially simultaneous cutting of tissue andhemostasis by coagulation, desirably minimizing patient trauma. Thecutting action is typically effected by an end-effector at the distalend of the instrument, with the end-effector transmitting ultrasonicenergy to tissue brought into contact therewith. Ultrasonic instrumentsof this nature can be configured for open surgical use, or laparoscopicor endoscopic surgical procedures.

Ultrasonic surgical instruments have been developed that include a clampmechanism to press tissue against the end-effector of the instrument inorder to couple ultrasonic energy to the tissue of a patient. Such anarrangement (sometimes referred to as an ultrasonic transector) isdisclosed in U.S. Pat. No. 5,322,055, hereby incorporated by reference.

In previous ultrasonic instruments, the waveguide of the instrument,through which ultrasonic energy is directed, is typically provided withone or more ring-like members for acoustically dampening the waveguide,and isolating the waveguide from surrounding components. Such isolationmembers are typically provided at one or more nodes of longitudinalvibration of the waveguide, and are typically constructed of elastomericmaterial, such as silicone rubber. Isolation members of this typedesirably prevent loss of vibrational energy from the waveguide whichcan occur under side-loading or bending conditions which might otherwisecause indirect contact of the waveguide with an associated componentpositioned thereabout.

In ultrasonic surgical instruments heretofore known for endoscopicapplications, the outside diameter of the elongated endoscopic portionof such instruments has been on the order of 10 mm. As such, it isordinarily been possible to provide suitable isolation members for thewaveguide of such instruments, while still providing a waveguide havinga sufficiently large cross-section for the desired rigidity and fordelivery of the desired level of ultrasonic energy without excessiveheating of the waveguide.

Continued development of ultrasonic surgical instruments has desirablyresulted in instruments having even smaller endoscopic portions, on theorder of 6 mm in diameter or less. When configuring ultrasonicinstruments of this relatively small size, it is important that thedesired acoustic dampening of the waveguide be effected, while stillproviding the waveguide with a cross-section which is as large aspracticable. Problems in isolating the waveguide can be particularlyexacerbated in ultrasonic instruments configured to effect clamping oftissue against an end-effector of the instrument, since such clampingcreates bending moments within the waveguide flexing the waveguide fromits normal, unloaded configuration.

The present invention is directed to an improved support member for anultrasonic surgical instrument, with the support member of the presentinvention particularly suited for use in instruments configured forendoscopic applications having relatively small cross-sections.

SUMMARY OF THE INVENTION

In accordance with the present invention, an ultrasonic surgical clampcoagulator apparatus is configured to permit selective cutting,coagulation, and clamping of tissue during surgical procedures. In orderto acoustically dampen the waveguide of the apparatus, the apparatusincludes an annular support member positioned at the distal-most node ofthe waveguide. The annular support member is configured to include asupport portion which acts to isolate the waveguide from surroundingcomponents, and a sealing portion which effects sealing between thewaveguide and a reciprocable tubular actuating member positioned aroundthe waveguide. By this construction, the annular support member dampensunwanted modes of vibration while allowing desired modes of vibration,effects sealing of the region about the waveguide, and maximizes thecross-sectional area available for the active waveguide within theelongated tubular portion of the instrument.

In accordance with the illustrated embodiment, the present ultrasonicsurgical clamp apparatus includes a housing, and an outer tubular sheathhaving a proximal end joined to the housing. An inner tubular actuatingmember is reciprocably positioned within the outer tubular sheath, andis operatively connected to a clamp arm pivotally mounted on a distalend of the outer tubular sheath. The clamp arm is mounted for pivotalmovement with respect to an end-effector of an ultrasonic waveguidepositioned within the inner tubular actuating member. In the illustratedembodiment, the outer tubular sheath, the inner tubular actuatingmember, and the ultrasonic waveguide are mounted for rotation togetherwith respect to the apparatus housing, with the actuating member beingreciprocable with respect to both the outer tubular sheath as well asthe ultrasonic waveguide positioned within the actuating member.Reciprocable movement of the actuating member pivotally moves the clamparm with respect to the end-effector of the waveguide.

In accordance with the present invention, an annular support member ismounted on the waveguide at a distal-most node thereof. The supportmember preferably comprises elastomeric material, such as siliconerubber, and is configured to provide a combination of functions forenhancing the performance of the apparatus. Specifically, the supportmember includes a support portion having a generally cylindrical outersupport surface which is positioned between the waveguide and theactuating member for resisting bending moments created during clampingof tissue against the end-effector by the pivotal clamp arm. The supportmember further includes a sealing portion for sealing the region betweenthe waveguide and the relatively reciprocable actuating member. In thepreferred embodiment, the sealing portion has a pair of convergingsurfaces which converge and meet each other to define a peripheralsealing region spaced radially outwardly of the outer cylindricalsupport surface of the support portion of the member.

In accordance with illustrated embodiments of the invention, the sealingportion of the support member is spaced axially from the support portionthereof, either distally or proximally. In alternate embodiments, thesealing portion of the support member is positioned medially of thesupport portion. For each of the various embodiments of the supportmember, the associated waveguide can be configured to include a lugportion having a diameter greater than the portions of the waveguideadjacent thereto. The support member of the present invention ispreferably positioned with respect to such a lug portion so that thissupport portion of the support member is positioned on and flanks thelug portion of the waveguide. In those embodiments of the presentsupport member wherein the sealing portion is positioned medially of thesupport portion, the sealing portion can be positioned in substantialalignment with the lug portion of the waveguide.

Other features and advantages of the present invention will becomereadily apparent from the following detailed description, theaccompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an ultrasonic surgical system includingan ultrasonic clamp coagulator apparatus embodying the principles of thepresent invention;

FIG 2 is an enlarged, fragmentary perspective view of a clamp mechanismof the clamp coagulator apparatus illustrated in FIG. 1;

FIG. 3 is a side elevational view, partially in cut-away, of the clampcoagulator embodying the principles of the present invention, shown inoperative association with an ultrasonic drive unit of the surgicalsystem shown in FIG. 1;

FIG. 4 is an exploded view of the ultrasonic surgical clamp coagulatorapparatus embodying the principles of the present invention;

FIG. 5 is an enlarged, fragmentary view of the present clamp coagulatorapparatus illustrating a clamp drive mechanism thereof and associateddetent mechanism;

FIG. 6 is a diagrammatic view further illustrating the clamp drivemechanism and detent mechanism of the present clamp coagulatorapparatus;

FIG. 7 is a diagrammatic view of the detent mechanism of the presentinvention;

FIG. 8 is a perspective view of a clamp mechanism drive collar of thepresent clamp coagulator apparatus;

FIG. 9 is a fragmentary, exploded perspective view illustrating awaveguide of the present apparatus, having a support member positionedthereon embodying the principles of the present invention, illustratedwith an associated reciprocable actuating member of the apparatus; and

FIG. 10-15 are fragmentary cross-sectional views of the waveguideillustrated in FIG. 9, with various embodiments of the support member ofthe present invention illustrated in position on the waveguide.

DETAILED DESCRIPTION

While the present invention is susceptible of embodiments in variousforms, there is shown in the drawings and will hereinafter be describeda presently preferred embodiment, with the understanding that thepresent disclosure is to be considered as an exemplification of theinvention, and is not intended to limit the invention to the specificembodiment illustrated.

The present invention is particularly directed to an improved ultrasonicsurgical clamp coagulator apparatus which is configured for effectingtissue coagulation, and/or clamping during surgical procedures. Thepresent apparatus can readily be configured for use in both opensurgical procedures, as well as laparoscopic or endoscopic procedures.Versatile use is facilitated by selective use of ultrasonic energy. Whenultrasonic components of the apparatus are inactive, tissue can bereadily gripped and manipulated, as desired, without tissue cutting ordamage. When the ultrasonic components are activated, the apparatuspermits tissue to be gripped for coupling with the ultrasonic energy toeffect tissue coagulation, with application of increased pressureefficiently effecting tissue cutting and coagulation. If desired,ultrasonic energy can be applied to tissue without use of the clampingmechanism of the apparatus by appropriate manipulation of the ultrasonic"blade" or end-effector of the device.

As will become apparent from the following description, the presentclamp coagulator apparatus is particularly configured for disposable useby virtue of its straightforward construction. As such, it iscontemplated that the apparatus be used in association with anultrasonic drive unit of a surgical system, whereby ultrasonic energyfrom the drive unit provides the desired ultrasonic actuation of thepresent clamp coagulator apparatus. It will be appreciated that a clampcoagulator apparatus embodying the principles of the present inventioncan be configured for non-disposable use, and non-detachably integratedwith an associated ultrasonic drive unit. However, detachable connectionof the present clamp coagulator apparatus with an associated ultrasonicdrive unit is presently preferred for single-patient use of theapparatus.

With reference first to FIGS. 1 and 3, therein is illustrated apresently preferred embodiment of a surgical system, generallydesignated 10, which includes an ultrasonic clamp coagulator apparatusembodying the principles of the present invention. Preferred details ofthe ultrasonic generator and associated ultrasonic drive unit of thesurgical system 10 will first be described, with subsequent detaileddescription of the ultrasonic surgical clamp coagulator apparatus,including a clamp mechanism configured for indexed rotation, embodyingthe principles of the present invention.

The surgical system 10 includes an ultrasonic generator 30 and anassociated ultrasonic surgical instrument. The surgical instrumentincludes an ultrasonic drive unit, designated 50, and an ultrasonicclamp coagulator apparatus 120 embodying the principles of the presentinvention. As will be further described, an ultrasonic transducer of thedrive unit 50, and an ultrasonic waveguide of the clamp coagulator 120,together provide an acoustic assembly of the present surgical system,with the acoustic assembly providing ultrasonic energy for surgicalprocedures when powered by generator 30. It will be noted that in someapplications, the ultrasonic drive unit 50 is referred to as a "handpiece assembly" because the surgical instrument of the surgical systemis configured such that a surgeon grasps and manipulates the ultrasonicdrive unit 50 during various procedures and operations. The clampcoagulator apparatus 120 embodying the principles of the presentinvention preferably includes a scissors-like grip arrangement whichfacilitates positioning and manipulation of the instrument apart frommanipulation of the ultrasonic drive unit 50.

The generator 30 of the surgical system sends an electrical signalthrough a cable 32 at a selected excursion, frequency, and phasedetermined by a control system of the generator 30. As will be furtherdescribed, the signal causes one or more piezoelectric elements of theacoustic assembly of the surgical instrument to expand and contract,thereby converting the electrical energy into mechanical motion. Themechanical motion results in longitudinal waves of ultrasonic energythat propagate through the acoustic assembly in an acoustic standingwave to vibrate the acoustic assembly at a selected frequency andexcursion. An end-effector at the distal end of the waveguide of theacoustic assembly is placed in contact with tissue of the patient totransfer the ultrasonic energy to the tissue. As further describedbelow, a surgical tool, such as, a jaw or clamping mechanism, ispreferably utilized to press the tissue against the end-effector.

As the end-effector couples with the tissue, thermal energy or heat isgenerated as a result of friction, acoustic absorption, and viscouslosses within the tissue. The heat is sufficient to break proteinhydrogen bonds, causing the highly structured protein (i.e., collagenand muscle protein) to denature (i.e., become less organized). As theproteins are denatured, a sticky coagulum forms to seal or coagulatesmall blood vessels. Deep coagulation of larger blood vessels resultswhen the effect is prolonged.

The transfer of the ultrasonic energy to the tissue causes other effectsincluding mechanical tearing, cutting, cavitation, cell disruption, andemulsification. The amount of cutting as well as the degree ofcoagulation obtained varies with the excursion of the end-effector, thefrequency of vibration, the amount of pressure applied by the user, thesharpness of the end-effector, and the coupling between the end-effectorand the tissue.

As illustrated in FIG. 1, the generator 30 includes a control systemintegral with the generator 30, a power switch 34, and a triggeringmechanism 36. The power switch 34 controls the electrical power to thegenerator 30, and when activated by the triggering mechanism 36, thegenerator 30 provides energy to drive the acoustic assembly of thesurgical system 10 at a predetermined frequency and to drive theend-effector at a predetermined excursion level. The generator 30 drivesor excites the acoustic assembly at any suitable resonant frequency ofthe acoustic assembly.

When the generator 30 is activated via the triggering mechanism 36,electrical energy is continuously applied by the generator 30 to atransducer stack or assembly 40 of the acoustic assembly. A phase-lockedloop in the control system of the generator 30 monitors feedback fromthe acoustic assembly. The phase lock loop adjusts the frequency of theelectrical energy sent by the generator 30 to match the resonantfrequency of the selected longitudinal mode of vibration of the acousticassembly including the tissue load. In addition, a second feedback loopin the control system maintains the electrical current supplied to theacoustic assembly at a preselected constant level in order to achievesubstantially constant excursion at the end-effector of the acousticassembly.

The electrical signal supplied to the acoustic assembly will cause thedistal end of the waveguide, i.e., the end-effector, to vibratelongitudinally in the range of, for example, approximately 20 kHz to 250kHz, and preferably in the range of about 54 kHz to 56 kHz, and mostpreferably at about 55.5 kHz. The excursion of the vibrations at theend-effector can be controlled by, for example, controlling theamplitude of the electrical signal applied to the transducer assembly 40of the acoustic assembly by the generator 30.

As noted above, the triggering mechanism 36 of the generator 30 allows auser to activate the generator 30 so that electrical energy may becontinuously supplied to the acoustic assembly. The triggering mechanism36 preferably comprises a foot activating switch that is detachablycoupled or attached to the generator 30 by a cable or cord.Alternatively, the triggering mechanism can be configured as a handswitch incorporated in the ultrasonic drive unit 50 to allow thegenerator 30 to be activated by a user.

The generator 30 also has a power line 38 for insertion in anelectro-surgical unit or conventional electrical outlet. It iscontemplated that the generator 30 can also be powered by a directcurrent (DC) source, such as a battery. The generator 30 can compriseany suitable generator, such as Model No. GENO1, available from EthiconEndo-Surgery, Inc.

Referring to FIGS. 1 and 3, the ultrasonic drive unit 50 of the surgicalinstrument includes a multi-piece housing 52 adapted to isolate theoperator from the vibrations of the acoustic assembly. The drive unithousing 52 can be shaped to be held by a user in a conventional manner,but it is contemplated that the present clamp coagulator 120 principallybe grasped and manipulated by a scissors-like arrangement provided by ahousing of the apparatus, as will be described. While the multi-piecehousing 52 is illustrated, the housing 52 may comprise a single orunitary component.

The housing 52 of the ultrasonic drive unit 50 generally includes aproximal end, a distal end, and a cavity extending longitudinallytherein. The distal end of the housing 52 includes an opening 60configured to allow the acoustic assembly of the surgical system 10 toextend therethrough, and the proximal end of the housing 52 is coupledto the generator 30 by the cable 32. The cable 32 preferably includesducts or vents 62 to allow air to be introduced into the housing 52 ofthe ultrasonic drive unit 50 to cool the transducer assembly 40 of theacoustic assembly.

The housing 52 of the ultrasonic drive unit 50 is preferably constructedfrom a durable plastic, such as Ultem®. It is also contemplated that thehousing 52 may alternatively be made from a variety of materialsincluding other plastics i.e. liquid crystal polymer (LCP), nylon, orpolycarbonate!. A suitable ultrasonic drive unit 50 is Model No. HP050,available from Ethicon Endo-Surgery, Inc.

The acoustic assembly of the surgical instrument generally includes afirst acoustic portion and a second acoustic portion. The first acousticportion is preferably carried by the ultrasonic drive unit 50, and thesecond acoustic portion (in the form of a waveguide and end-effector, aswill be described) is carried by the ultrasonic clamp coagulatorapparatus. The distal end of the first acoustic portion is operativelycoupled to the proximal end of the second acoustic portion preferably bya threaded connection.

As shown in FIG. 3, the first acoustic portion includes the transducerstack or assembly 40 and a mounting device 84, and the second acousticportion includes a transmission component or working member, referred toherein as a waveguide having an end-effector.

The components of the acoustic assembly are preferably acousticallytuned such that the length of each component is an integral number ofone-half wavelengths (nλ/2), where the wavelength λ is the wavelength ofa preselected or operating longitudinal vibration frequency f₀ of theacoustic assembly, and n is any non-negative integer. It is alsocontemplated that the acoustic assembly may incorporate any suitablearrangement of acoustic elements.

The transducer assembly 40 of the acoustic assembly converts theelectrical signal from the generator 30 into mechanical energy thatresults in longitudinal vibratory motion of the end-effector atultrasonic frequencies. When the acoustic assembly is energized, avibratory motion standing wave is generated through the acousticassembly. The excursion of the vibratory motion at any point along theacoustic assembly depends on the location along the acoustic assembly atwhich the vibratory motion is measured. A minimum or zero crossing inthe vibratory motion standing wave is generally referred to as a node(i.e., where motion is usually minimal), and an absolute value maximumor peak in the standing wave is generally referred to as an anti-node.The distance between an anti-node and its nearest node is one-quarterwavelength (λ/4).

As shown in FIG. 3, the transducer assembly 40 of the acoustic assembly,which is also known as a "Langevin stacks", generally includes atransduction portion 90, a first resonator 92, and a second resonator94. The transducer assembly is preferably an integral number of one-halfsystem wavelengths (nμ/2) in length. It is to be understood that thepresent invention may be alternatively configured to include atransducer assembly comprising a magnetostrictive, electromagnetic orelectrostatic transducer.

The distal end of the first resonator 92 is connected to the proximalend of transduction section 90, and the proximal end of the secondresonator 94 is connected to the distal end of transduction portion 90.The first and second resonators 92 and 94 are preferably fabricated fromtitanium, aluminum, steel, or any other suitable material, and mostpreferably, the first resonator 92 is fabricated from 303 stainlesssteel and the second resonator 94 is fabricated from 7075-T651 Aluminum.The first and second resonators 92 and 94 have a length determined by anumber of variables, including the length of the transduction section90, the speed of sound of material used in the resonators 92 and 94, andthe desired fundamental frequency f₀ of the transducer assembly 40. Thesecond resonator 94 can be tapered inwardly from its proximal end to itsdistal end to function as a velocity transformer and amplify theultrasonic vibration excursion.

The transduction portion 90 of the transducer assembly 40 preferablycomprises a piezoelectric section of alternating positive electrodes 96and negative electrodes 98, with piezoelectric elements 100 alternatingbetween the electrodes 96 and 98. The piezoelectric elements 100 can befabricated from any suitable material, such as, for example, leadzirconate-titanate, lead metaniobate, lead titanate, or otherpiezoelectric material. Each of the positive electrodes 96, negativeelectrodes 98, and piezoelectric elements 100 have a bore extendingthrough the center. The positive and negative electrodes 96 and 98 areelectrically coupled to wires 102 and 104, respectfully. The wires 102and 104 transmit the electrical signal from the generator 30 toelectrodes 96 and 98.

As illustrated in FIG. 3, the piezoelectric elements 100 are held incompression between the first and second resonators 92 and 94 by a bolt106. The bolt 106 preferably has a head, a shank, and a threaded distalend. The bolt 106 is inserted from the proximal end of the firstresonator 92 through the bores of the first resonator 92, the electrodes96 and 98, and piezoelectric elements 100. The threaded distal end ofthe bolt 106 is screwed into a threaded bore in the proximal end ofsecond resonator 94. The bolt can be fabricated from steel, titanium,aluminum, or other suitable material and is preferably fabricated fromTi-6Al-4V Titanium, and most preferably from 4037 low alloy steel.

The piezoelectric elements 100 are energized in response to theelectrical signal supplied from the generator 30 to produce an acousticstanding wave in the acoustic assembly. The electrical signal causes anelectro-magnetic field across the piezoelectric elements 100, causingthe piezoelectric elements 100 to expand and contract in a continuousmanner along the axis of the voltage gradient, producing high frequencylongitudinal waves of ultrasonic energy. The ultrasonic energy istransmitted through the acoustic assembly to the end-effector.

The mounting device 84 of the acoustic assembly has a proximal end, adistal end, and preferably has a length substantially equal to anintegral number one-half system wavelengths. The proximal end of themounting device 84 is preferably axially aligned and coupled to thedistal end of the second resonator 94 by an internal Treaded connectionnear an anti-node. (For purposes of this disclosure, the term "near" isdefined as "exactly at" or "in close proximity to".) It is alsocontemplated that the mounting device 84 may be attached to the secondresonator 94 by any suitable means, and the second resonator 94 andmounting device 84 may be formed as a single or unitary component.

The mounting device 84 is coupled to the housing 52 of the ultrasonicdrive unit 50 near a node. The mounting device 84 preferably includes anintegral mounting flange 108 disposed around its periphery. The mountingflange 108 is preferably disposed in an annular groove 110 formed in thehousing 52 of the ultrasonic drive unit 50 to couple the mounting device84 to the housing 52. A compliant member or material 112, such as a pairof silicone rubber O-rings attached by stand-offs, may be placed betweenthe annular groove 110 of the housing 52 and the integral flange 108 ofthe mounting device 86 to reduce or prevent ultrasonic vibration frombeing transmitted from the mounting device 84 to the housing 52.

The mounting device 84 is preferably secured in a predetermined axialposition by a plurality of pins 114, preferably four. The pins 114 aredisposed in a longitudinal direction ninety (90) degrees apart from eachother around the outer periphery of the mounting device 84. The pins 114are coupled to the housing 52 of the ultrasonic drive unit 50 and aredisposed through notches in the acoustic mounting flange 108 of themounting device 84. The pins 114 are preferably fabricated fromstainless steel.

The mounting device 84 is preferably configured to amplify theultrasonic vibration excursion that is transmitted through the acousticassembly to the distal end of the end-effector. In one preferredembodiment, the mounting device 84 comprises a solid, tapered horn. Asultrasonic energy is transmitted through the mounting device 84, thevelocity of the acoustic wave transmitted through the mounting device 84is amplified. It is contemplated that the mounting device 84 beconfigured as any suitable shape, such as, for example, a stepped horn,a conical horn, an exponential horn, a unitary gain horn, or the like.

As shown in FIG. 3, the mounting device 84 is preferably acousticallycoupled to the second acoustic portion of the ultrasonic clampcoagulator apparatus 120. The distal end of the mounting device 84 ispreferably coupled to the proximal end of the second acoustic portion byan internal threaded connection near an anti-node, but alternativecoupling arrangements can be employed.

Referring now to FIG. 4, an exploded view of the ultrasonic clampcoagulator apparatus 120 of the surgical system 10 in accordance with apreferred embodiment is illustrated. The proximal end of the ultrasonicclamp coagulator apparatus 120 preferably receives and is fitted to thedistal end of the ultrasonic drive unit 50 by insertion of the driveunit into the housing of the apparatus, as shown in FIG. 3. Theultrasonic clamp coagulator apparatus 120 is preferably attached to andremoved from the ultrasonic drive unit 50 as a unit. The ultrasonicclamp coagulator 120 may be disposed of after a single use.

The ultrasonic clamp coagulator apparatus 120 preferably includes ahandle assembly or a housing 130, preferably comprising mating housingportions 131, 132, and an elongated or endoscopic portion 150. When thepresent apparatus is configured for endoscopic use, the construction canbe dimensioned such that portion 150 has an outside diameter of about5.5 Mm. The elongated portion 150 of the ultrasonic clamp coagulatorapparatus 120 extends orthogonally from the apparatus housing 130. Theelongated portion 150 can be selectively rotated with respect to thehousing 130 as further described below. The elongated portion 150preferably includes an outer tubular member or sheath 160, an innertubular actuating member 170, and the second acoustic portion of theacoustic system in the form of a waveguide 180 having an end-effector180'. As will be described, the outer sheath 160, the actuating member170, and the waveguide 180 are preferably joined together for indexedrotation as a unit (together with ultrasonic drive unit 50) relative tohousing 130.

As illustrated in FIG. 4, the proximal end of the waveguide 180 of thesecond acoustic portion is preferably detachably coupled to the mountingdevice 84 of the ultrasonic drive unit 50 near an anti-node as describedabove.

The waveguide 180 preferably has a length substantially equal to aninteger number of one-half system wavelengths (nλ/2). The waveguide 180is preferably fabricated from a solid core shaft constructed out ofmaterial which propagates ultrasonic energy efficiently, such astitanium alloy (i.e., Ti-6Al-4V) or an aluminum alloy. It iscontemplated that the waveguide 180 can alternatively be fabricated fromany other suitable material.

The waveguide is preferably substantially semi-flexible. It will berecognized that the waveguide can alternatively be substantially rigidor may comprise a flexible wire. The waveguide may be configured toamplify the is mechanical vibrations transmitted through the waveguideto the end-effector as is well known in the art. The waveguide mayfurther have features to control the gain of the longitudinal vibrationalong the waveguide and features to tune the waveguide to the resonantfrequency of the system.

It will be recognized that the waveguide 180 may have any suitablecross-sectional dimension. For example, the waveguide may have asubstantially uniform cross-section or the waveguide may be tapered atvarious sections or may be tapered along its entire length.

As shown in FIG. 4, the waveguide 180 generally has a first section 182,a second section 184, and a third section 186. The first section 182 ofthe waveguide extends distally from the proximal end of the waveguide,and has a substantially continuous cross-section dimension.

The first section 182 preferably includes at least one radial hole oraperture 188 extending diametrically therethrough, substantiallyperpendicular to the axis of the waveguide 180. The aperture 188 ispreferably positioned at a node, but may be otherwise positioned. Itwill be recognized that the aperture 188 may have any suitable depth andmay be any suitable shape. The aperture is configured to receive aconnector pin member which connects the waveguide 180, the tubularactuating member 170, and the tubular outer sheath 160 together forconjoint, indexed rotation relative to apparatus housing 130.

The second section 184 of the waveguide 180 extends distally from thefirst section 182. The second section 184 preferably also has asubstantially continuous cross-section. The diameter of the secondsection 184 is smaller than the diameter of the first section 182 andlarger than the diameter of the third section 186. As ultrasonic energypasses from the first section 182 of the waveguide 180 into the secondsection 184, the narrowing of the second section 184 will result in anincreased amplitude of the ultrasonic energy passing therethrough.

The third section 186 extends distally from the distal end of the secondsection 184. The third section 186 also has a substantially continuouscross-section. The third section 186 may also include small diameterchanges along its length. As ultrasonic energy passes from the secondsection 184 of the waveguide 180 into the third section 186, thenarrowing of the third section 186 will result in an increased amplitudeof the ultrasonic energy passing therethrough.

The third section 186 may have a plurality of grooves or notches (notshown) formed in its outer circumference. The grooves may be located atnodes of the waveguide 180 to act as alignment indicators for theinstallation of a damping sheath (not shown) and stabilizing siliconerings or compliant supports during manufacturing. Such compliantsupports desirably act to isolate the active waveguide 180 formsurrounding components of the apparatus. A seal is preferably providedat the distal-most node, nearest the end-effector 180', to abate passageof tissue, blood, and other material in the region between the waveguideand actuating member 170. As her described hereinafrer, and inaccordance with the present invention, a support member is preferablyprovided at the distal-most node to resist bending moments created inthe waveguide by the associated clamping mechanism, and to effectsealing of the region between the waveguide and actuating member 170.Even though it is contemplated that the support member be relativelythin (with regions as thin as about 0.003 to 0.005 inches) to providethe desired support, acoustic isolation of the active waveguide fromactuating member 170 is effected.

The end-effector 180' of the waveguide 180 is preferably integraltherewith and formed as a single unit. The end-effector may alternatelybe connected by a threaded connection, or by a welded joint. The distalend of the end-effector is disposed near an anti-node in order to tunethe acoustic assembly to a preferred resonant frequency f₀ when theacoustic assembly is not loaded by tissue. When the transducer assemblyis energized, the distal end of the end-effector is configured to movelongitudinally in the range of, for example, approximately 10-500microns peak-to-peak, and preferably in the range of about 10 to about100 microns at a predetermined vibrational frequency f₀.

In accordance with the illustrated embodiment, the end-effector 180',sometimes referred to as a blade, is preferably cylindrical forcooperation with the associated clamping mechanism of the present clampcoagulator apparatus. The end-effector may receive suitable surfacetreatment, as is known in the art.

With particular reference to FIG. 2, therein is illustrated the clampingmechanism of the present clamp coagulator 120, which is configured forcooperative action with the end-effector 180' of the waveguide 180. Theclamping mechanism includes a pivotally movable clamp arm 190, which ispivotally connected at the distal end thereof to the distal end of outertubular sheath 160. A clamp pad 192, preferably formed from Teflon orother suitable low-friction material, is mounted on the surface of theclamp arm for cooperation with the end-effector 180', with pivotalmovement of the clamp arm positioning the clamp pad in substantiallyparallel relationship to, and in contact with, the end-effector 180'. Bythis construction, tissue to be clamped is grasped between the pad 192and the end effector 180'. As illustrated, the pad 192 is preferablyprovided with a sawtooth-like configuration to enhance the gripping oftissue in cooperation with the end-effector 180'.

Pivotal movement of the clamp arm with respect to the end-effector iseffected by the provision of at least one, and preferably a pair oflever portions 193 of the clamp arm 190 at the proximal end thereof. Thelever portions are positioned on respective opposite sides of thewaveguide 180 and end-effector 180', and are in operative engagementwith a drive portion 194 of the reciprocable actuating member 170.Reciprocable movement of the actuating member, relative to the outertubular sheath 160 and the waveguide 180, thereby effects pivotalmovement of the clamp arm relative to the end-effector. The leverportions 193 can be respectively positioned in a pair of openingsdefined by the drive portion 194, or otherwise suitably mechanicallycoupled therewith, whereby reciprocable movement of the actuating memberacts through the drive portion 194 and lever portions 193 to pivot theclamp arm.

With particular reference to FIGS. 3, 5, and 6, reciprocable movement ofthe actuating member 170 is effected by the provision of a drive collar,generally designated 200, mounted on the proximal end of the actuatingmember for conjoint rotation. To this end, the drive collar includes apair of diametrically opposed axially extending arms 202 each having adrive lug 204, with the drive lugs being biased by the arms 202 intoengagement with suitable openings 206 defined by the proximal portion oftubular actuating member 170. Rotation of the drive collar 200 togetherwith the actuating member 170 is further effected by the provision of apair of keys 208 (see FIG. 8) diametrically engageable with suitableopenings 210 defined by the proximal end of the actuating member 170. Acircumferential groove 211 on the actuating member 170 receives onO-ring 211' (FIG. 4) for engagement with the inside surface of outersheath 160.

Rotation of the actuating member 170 together with tubular outer sheath160 and inner waveguide 180 is provided by a connector pin 212 extendingthrough these components of the apparatus. As illustrated in FIG. 4, thetubular actuating member 170 defines an elongated slot 214 through whichthe connector pin 212 extends to accommodate reciprocable movement ofthe actuating member relative to the outer tubular sheath and innerwaveguide.

A rotation knob 216 mounted on the outer tubular sheath facilitatesrotational positioning of the elongated portion 150 with respect to thehousing 130 of the clamp coagulator apparatus. Connector pin 212preferably joins knob 216 together with sheath 160, member 170, andwaveguide 180 for rotation as a unit relative to housing 130. In acurrent embodiment, hub portion 216' of the rotation knob acts torotatably mount the outer sheath 160, the actuating member 170, and thewaveguide 180 (as a unit with knob 216), on the housing 130.

The drive collar 200 provides a portion of the clamp drive mechanism ofthe apparatus which effects pivotal movement of the clamp arm 190 byreciprocation of actuating member 170. The clamp drive mechanism furtherincludes a drive yoke 220 which is operatively connected with anoperating lever 222 of the apparatus, with the operating lever thusinterconnected with the reciprocable actuating member 170 via drive yoke220 and drive collar 200. The operating lever 222 is pivotally connectedto the housing 130 of the apparatus (by a pivot mount 223) forcooperation in a scissors-like fashion with a handgrip portion 224 ofthe housing. Movement of lever 222 toward handgrip portion 224translates actuating member 170 proximally, thereby pivoting clamp arm190 toward end-effector 180'.

Operative connection of the drive yoke 220 with the operating lever 222is provided by a spring 226, preferably comprising a compression coilspring. The spring 226 fits within a spring slot 228 defined by thedrive yoke 220, which in turn is positioned between a pair of springretainer flanges 230 of the operating lever 222. The drive yoke 220 ispivotally movable with respect to the spring flanges 230 (about pivotmount 223 of housing 130) in opposition to the compression coil spring,which bears against the surfaces of the spring slots defined by each ofthe spring flanges 230. In this manner, the force which can be appliedto the actuating member 170, by pivotal movement of operating lever 222acting through drive yoke 220 and drive collar 200, is limited by theforce with which spring 226 bears against the spring flanges 230.Application of excessive force results in pivotal displacement of driveyoke 220 relative to the spring flanges 230 of the operating lever 222in opposition to spring 226. In a presently preferred embodiment, spring226 is selected to limit clamping force at clamp arm 190 toapproximately 2 pounds. Stop portions of housing 130 limit the travel ofoperating lever 222 to prevent excessive compression of spring 226.

Indexed rotational positioning of the elongated portion 150 of thepresent clamp coagulator apparatus 120 is provided by the provision of adetent mechanism incorporated into the clamp drive mechanism of theapparatus. Specifically, the drive collar 200 includes a pair of axiallyspaced apart drive flanges 232. A detent-receiving surface is providedbetween the drive flanges 232, and defines a plurality ofcircumferentially spaced teeth 234 which define detent-receivingdepressions generally about the periphery of the drive collar 200. In apresently preferred embodiment, twelve (12) of the teeth 234 areprovided, thereby providing indexed positioning of the elongated portion150 of the apparatus at 30° intervals relative to the housing 130 of theapparatus.

Indexed rotational movement is further achieved by the provision of atleast one, and preferably a pair, of diametrically opposed detents 236respectively provided on cantilevered yoke arms 238 of drive yoke 220.By this arrangement, the yoke arms 238 are positioned between the driveflanges 232 for engagement with the confronting surfaces thereof andbias the detents 236 into engagement with the drive collar 200. Indexedrelative rotation is thus achieved, with the detents 236 of the yokearms cooperating with the drive flanges 238 for effecting reciprocationof the actuating member 170. In a presently preferred embodiment, thedrive yoke 220 is formed from suitable polymeric material, with thebiasing force created by the yoke arms acting on the detents thereofcooperating with the radial depressions defied by the drive collar toresist relative rotational torque less than about 5 to 20 inch-ounces.As such, the elongated portion 150 of the clamp coagulator apparatus ismaintained in any of its selected indexed rotational positions, relativeto housing 130, unless a torque is applied (such as by rotation knob216) exceeding this predetermined torque level. A snap-like indexingaction is thus provided.

Rotation of the elongated proportion 150 of the present clamp coagulatorapparatus 120 is preferably effected together with relative rotationalmovement of ultrasonic drive unit 50 with respect to apparatus housing130. In order to join the elongated portion 150 to the ultrasonic driveunit 50 in ultrasonic-transmitting relationship, the proximal portion ofthe outer tubular sheath 160 is preferably provided with a pair ofwrench flats 240 (see FIG. 4). The wrench flats allow torque to beapplied by a suitable torque wrench or the like to thereby permit thewaveguide 180 to be joined to the ultrasonic drive unit 50. Theultrasonic drive unit, as well as the elongated portion 150, are thusrotatable, as a unit, by suitable manipulation of rotation knob 216,relative to housing 130 of the apparatus. The interior of housing 130 isdimensioned to accommodate such relative rotation of the drive unit 50.

As noted above, the present surgical clamp coagulator apparatuspreferably includes a support member positioned at the distal-most nodeof the waveguide 180 to resist bending moments created in the waveguideby pivotal movement of clamp arm 190 against end-effector 180'. Asupport member, designated 250 in FIGS. 9-15, and embodying theprinciples of the present invention, is particularly preferred by virtueof the combination of support and sealing functions provided by thesupport member. The support member has been particularly configured topermit the waveguide 180 to be provided with a relatively largecross-sectional area, even though the outer tubular sheath 160 ofelongated portion 150 of the present surgical apparatus is preferablyprovided with an outside diameter less than about 6 mm. The supportmember desirably acts to acoustically isolate the active waveguide 180from the surrounding actuating member 170, while providing support toresist bending moments created in the waveguide, as well as effectingsealing between the waveguide and the relatively reciprocable actuatingmember. illustrated in FIG. 9 and 10, the annular support member 250includes an annular support portion 252 having a generally cylindricalouter support surface which is positioned for engagement with theinterior of reciprocable support member 170. The support member 250 ispreferably formed from elastomeric material, such a silicone rubber,thus providing the desired compliance for the sealing function of thesupport member. However, it is contemplated that the support portion 252be formed sufficiently thin to minimize its compression to aid inresisting bending moments created in the waveguide, particularly at thedistal-most node thereof, as clamp arm 190 presses tissue againstend-effector 180'. It is contemplated that the thickness of the supportportion, at its thinnest region, be on the order of 0.003-0.005 inches,and formed from material exhibiting a durometer on the order of 60 ShoreA. Even when configured to include such relatively thin regions, thesupport member still provides desired acoustic isolation for thewaveguide.

As illustrated, the support member 250 further includes an integralannular sealing portion 254. In the embodiments of the support member250 illustrated in FIGS 10 and 11, the sealing portion 254 is spacedaxially distally from the support portion 252. As shown, the sealingportion 254 preferably includes a pair of converging surfaces (eachpreferably generally frusto-conical), which converge and meet each otherto define a thin and compliant peripheral sealing region of the sealingportion 254. In a non-compressed state, this sealing region is spacedradially outwardly of the support surface of the support portion 252.This preferred configuration of the sealing member accommodatesreciprocation of tubular actuating member 170 with respect to thewaveguide 180, while desirably sealing the region between the waveguideand the actuating member against fluids and other material encounteredin surgery. It is preferred that an annular recess 255 be providedintermediate support portion 252 and sealing portion 154 (in thoseembodiments in which the sealing portion is spaced axially of thesupport portion) to accommodate deflection of the sealing portion towardthe support portion attendant to relative reciprocation of the actuatingmember 170.

As shown, the sealing member 250 is preferably positioned with respectto the distal-most node, designated "N" in the illustrations, such thatthe support portion 252 is generally centered with respect to the node.As will be observed, the embodiment of FIG. 11 differs from theembodiment of FIG. 10, in that the waveguide 180 is provided with a lugportion 181 having an outside diameter which is greater than theportions of the waveguide adjacent to the lug portion. In thisembodiment of support member 250, the support portion 252 is preferablycentered at the node "N", and is positioned on and flanks the lugportion of the waveguide. The lug portion acts to maintain the supportmember in position of the waveguide attendant to relative reciprocationof actuating member 170.

Referring now to the embodiments of FIGS. 12 and 13, the embodiments ofthe support member 250 illustrated therein are generally similar to theembodiments illustrated in FIGS. 10 and 11, respectively. However, theembodiments of FIGS. 12 and 13 differ in that the sealing portion 254 ofeach illustrated support member 250 is spaced axially proximally of thecorresponding support portion 252. Again, in the embodiment illustratedin FIG. 13 wherein waveguide 180 includes a lug portion 181, the supportportion 252 is preferably positioned an and flanks the lug portion.

Referring now to FIGS. 14 and 15, further alternate embodiments of thepresent support member, designated 350, are illustrated. Each of theseembodiments also include a support portion, designated 352, having agenerally cylindrical outer support surface. These embodiments furtherinclude a sealing portion, designated 354, having a pair of convergingsurfaces which converge and meet to define a peripheral sealing regionspaced radially outwardly of the outer support surface. In distinctionfrom previous embodiments, these embodiments include a sealing portion354 which is positioned medially of the support portion 352. In theembodiment of FIG. 15, wherein waveguide includes a lug portion 181, thesealing portion 354 is positioned in substantial alignment with the lugportion of the waveguide.

A support member embodying the principles of the present inventiondesirably isolates the ultrasonic vibration transmitted throughwaveguide 180 from the surrounding sheath, in particular, tubularactuating member 170.

Disposition of the present support member at the distal-most node of thewaveguide desirably resists bending moments created in the waveguide asthe clamping mechanism of the apparatus is operated. Disposition at thedistal-most node of the waveguide also effects sealing of the regionbetween the waveguide and the actuating member. While formation of thepresent support member from silicone rubber is presently preferred, itwill be understood that other materials may alternatively be employed.

Thus, the present surgical clamp coagulator apparatus is configured forhighly efficient and versatile use, with the construction beingsufficiently straight-forward and economical in configuration to permitsingle-patient use.

Components of the apparatus can be fabricated from materials suited forsurgical applications. By virtue of the detent mechanism provided bycooperation of drive collar 200 and drive yoke 220, selective angularpositioning of the elongated portion 150 of the apparatus, and theassociated ultrasonic drive unit 50, is readily effected with respect tothe housing 130 of the apparatus. The scissors-like action provided bypivotal operating lever 222 and cooperating handgrip portion 224facilitates convenient and efficient manipulation and positioning of theapparatus, and operation of the clamping mechanism at the distal portionof the apparatus whereby tissue is efficiently urged against theend-effector 180'. The detent mechanism resists rotation of theultrasonic drive unit, and associated cable assembly, with respect tothe housing 130 with the resistence to rotation readily and convenientlyovercome by application of sufficient torque via rotation knob 216. Thepreferred provision of a combination support and sealing member at thedistal-most node of the apparatus further facilitate efficient operationand configuration of the instrument with a selectively smallcross-section.

From the foregoing, it will be observed that numerous modifications andvariations can be effected without departing from the true spirit andscope of the novel concept of the present invention. It is to beunderstood that no limitation with respect to the specific embodimentillustrated herein is intended or should be inferred. The disclosure isintended to cover, by the appended claims, all such modifications asfall within the scope of the claims.

What is claimed is:
 1. An ultrasonic surgical clamp apparatuscomprising:a housing; an outer tubular sheath having a proximal endjoined to said housing, and a distal end; an inner actuating memberreciprocably positioned within said outer tubular sheath; an ultrasonicwaveguide positioned within said inner tubular actuating member andhaving an end-effector extending distally of said distal end of saidouter tubular sheath, said actuating member being reciprocable relativeto said waveguide; a clamp arm pivotally mounted on said distal end ofsaid outer tubular sheath for pivotal movement with respect to saidend-effector for clamping tissue between said clamp arm and saidend-effector, said clamp arm being operatively connected to saidactuating member so that reciprocable movement of said actuating memberpivotally moves said clamp arm with respect to said end-effector; and anannular support member mounted on said waveguide at a distal-most nodethereof for resisting bending moments created during clamping of tissueagainst said end-effector by said clamp arm, and for sealing the regionbetween said waveguide and said relatively reciprocable actuatingmember.
 2. An ultrasonic surgical clamp apparatus in accordance withclaim 1, whereinsaid support member includes a support portion having agenerally cylindrical outer support surface, and a sealing portionhaving a pair of converging surfaces which converge to define aperipheral sealing region which in a non-compressed state is spacedradially outwardly of said outer support surface.
 3. An ultrasonicsurgical clamp apparatus in accordance with claim 2, whereinsaid sealingportion of said support member is spaced axially from said supportportion.
 4. An ultrasonic surgical clamp apparatus in accordance withclaim 2 whereinsaid sealing portion of said support member is positionedmedially of said support portion.
 5. An ultrasonic surgical clampapparatus in accordance with claim 2, whereinsaid waveguide includes alug portion at said distal-most node having an outer cylindrical surfacehaving a diameter greater than portions of said waveguide adjacent tosaid lug portion, said support portion of said support member beingpositioned on and flanking said lug portion of said waveguide tomaintain said support member in position on said waveguide attendant torelative reciprocation of said actuating member.
 6. An ultrasonicsurgical clamp apparatus in accordance with claim 5, whereinsaid sealingportion of said support member is positioned medially of said supportportion, and in substantial alignment with said lug portion of saidwaveguide.
 7. An ultrasonic surgical clamp apparatus in accordance withclaim 1, whereina thinnest region of said support portion has athickness of about 0.003-0.005 inches.
 8. An ultrasonic surgical clampapparatus comprising:a housing; an outer tubular sheath having aproximal end joined to said housing, and a distal end, an inneractuating member reciprocably positioned within said outer tubularsheath; an ultrasonic waveguide positioned within said inner tubularactuating member and having an end-effector extending distally of saiddistal end of said outer tubular sheath, said actuating member beingreciprocable relative to said waveguide; a clamp arm pivotally mountedon said distal end of said outer tubular sheath for pivotal movementwith respect to said end-effector for clamping tissue between said clamparm and said end-effector, said clamp arm being operatively connected tosaid actuating member so that reciprocable movement of said actuatingmember pivotally moves said clamp arm with respect to said end-effector;and an annular support member mounted on said waveguide at a distal-mostnode thereof for acoustically isolating said waveguide from saidactuating member, said support member comprising elastomeric materialand including a support portion positioned between said waveguide andactuating member for resisting bending moments created during clampingof tissue against said end-effector by said clamp arm, said supportmember further including a sealing portion spaced axially from saidsupport portion for sealing the region between said waveguide and saidrelatively reciprocable actuating member.
 9. An ultrasonic surgicalclamp apparatus in accordance with claim 8, whereinsaid support memberincludes a support portion having a generally cylindrical outer supportsurface, and a sealing portion having a pair of converging surfaceswhich converge to define a peripheral sealing region which, in anon-compressed state, is spaced radially outwardly of said outer supportsurface.
 10. An ultrasonic surgical clamp apparatus in accordance withclaim 8, whereinsaid sealing portion of said support member is spaceddistally of said support portion.
 11. An ultrasonic surgical clampapparatus in accordance with claim 8, wherein said sealing portion ofsaid support member is spaced proximally of said support portion.
 12. Anultrasonic surgical clamp apparatus in accordance with claim 8,whereinsaid waveguide includes a lug portion at said distal-most nodehaving an outer cylindrical surface having a diameter greater thanportions of said waveguide adjacent to said lug portion, said supportportion of said support member being positioned on and flanking said lugportion of said waveguide to maintain said support member in position onsaid waveguide attendant to relative reciprocation of said actuatingmember.
 13. An ultrasonic surgical clamp apparatus in accordance withclaim 8, whereinsaid outer tubular sheath has an outside diameter lessthan about 6 mm.
 14. An ultrasonic surgical clamp apparatus inaccordance with claim 7 whereinsaid support member defines an annularrecess positioned intermediate said support portion and said sealingportion for accommodating deflection of said sealing portion attendantto relative reciprocation of said actuating member.